Thermostatic control device and system utilizing the same

ABSTRACT

Electrical switch means carried by frame means. A U-shaped bimetal member defining a pair of legs interconnected at adjacent ends thereof by an elbow portion pivotally mounted to the frame means. A plunger means is movably carried by the frame means and is disposed between one of the legs of the bimetal member and the switch means to operate the switch means in relation to the position of the one leg relative to the frame means. Cam means is movably carried by the frame means and acts on the other leg of the bimetal member to adjust the pivotal position of the bimetal member and, thus, the temperature setting that the thermostatic device will open the switch means, the cam means being movable across the longitudinal axis of the other leg of the bimetal member to adjust the same.

Unite States Patent Rosenberg et alg 51 May 23, 1972 THERMOSTATIC comm.DEVICE AND SYSTEM UTILIZING THE SAME Primary Examiner-Volodymyr Y.Mayewsky Assistant Examiner-F. E. Bell Attorney-Auzville Jackson, In,Robert L. Marben and Can- [72] Inventors: David M. Rosenberg; SiegfriedE. dor. Candor 8:. Tassone Manedte, both of Indiana, Pa. [57] ABSTRACT[73] Assignee: Robertshaw Conn-ob Company, I

Ri h d v Electrical suntch means earned by frame means. A U-shapedbimetal member defining a pair of legs interconnected at ad- [221 Med:Oct jacent ends thereof by an elbow portion pivotally mounted to [2!]Appl No; 79,122 the frame means. plunger means is movably carried by theframe means and IS disposed between one of the legs of the bimetalmember and the switch means to operate the switch [52] US. 353 means inrelation to the position of the one leg relative to the [5 Ill- 37/12frame means. Cam means is movably carried by the frame l l, 347, 349,means and acts on [he othe leg of [ha member to ad- 379 just the pivotalposition of the bimetal member and, thus, the temperature setting thatthe thermostatic device will open the [56] References Cited switchmeans, the cam means being movable across the longitudinal axis of theother leg of the bimetal member to adjust UNITED STATES PATENTS the same2,493,294 l/l950 Kronmiller ....337/347 2,786,917' 3/1957 Casey ..337/111 Cm WWW FOREIGN PATENTS OR APPLICATIONS 565,252 11/ 1944 Great Britain..337/360 91 23 39 J58 I 96" 59 28- s6 76 5 45 86-- 2 48 27 47 88- 40 4-7s- 73 I 49 74 63 77' 6O 56 l I J 8' 79 85 22 8O 35 a4 Patented May 23,1972 3,665,363

4 Sheets-$118913 1 3 INVENTORS DAVID M. ROSENBERG SIEGFRiED E. MANECKEBY W,M;W

THEIR ATTORNEYS Patented May 23, 1972 3,665,363

4 Sheets-Sheet 2 30 86 3o 27 27 28 88 78 FIGS 47* 51 e2 FIG.6

INVENTORS ID M. SENBERG GFRl E. MANECKE 2 V BY j FA ZW M;%

TH EIR ATTORN EYS Patented May'23, 1972 3,665,363

4 Sheets-Sheet 5 FIG. 8

INVENTORS DAVID M. ROSENBERG BY SIEGFRIED E. MANECKE 1 64A 63A 65A ET 3a I g r THEIR ATTORNEYS Patented May 23, 1972 3,665,363

4 Sheets-Sheet 4 INVE O DAVID M. ROSE E SIEGFRIED EMANECKE THEIR ATTORNEYS THERMOSTATIC CONTROL DEVICE AND SYSTEM UTILIZING THE SAME Thisinvention relates to an improved thermostatic control device as well asto an improved system utilizing such a control device or the like.

It is well known that thermostatic devices have been provided forcontrolling heating means and the like that is disposedremote from thethermostatic device, the thermostatic device sensing room temperatureand causing the heating means for the room or the like to turn on whenthe temperature of the room falls below a selected temperature as wellas causing the heating means to turn off when the room temperatureexceeds the selected temperature. Such thermostatic device has anauxiliary heater therein which only operates when the heating means isin its on condition to raise the temperatureat the thermostat to causethe thermostat to turn off the heating means before the temperature inthe room exceeds the selected temperature so as to prevent an adverseovershoot situation and thereby provide a narrow temperaturedifierential in the room or rooms being maintained by such thermostaticmeans.

Accordingly,-it is a feature of this invention to provide an improvedthermostatic device of the above type.

In particular, one embodiment of this invention provides a framemeans'carrying electrical switch means. A U-shaped bimetal member thatdefines a pair of legs interconnected together at adjacent ends thereofby an elbow portion is pivotally mounted by the elbow portion thereof tothe frame means. A movable plunger is carried by the framemeans and isdisposed between one of the legs of the bimetal member and the switchmeans to operate the switch means in relation to the position of the oneleg relative to the frame means. Cam means is movably carried by theframe means and acts on the other leg of the bimetal member to adjustthe pivotal position of the bimetal member and, thus, thetemperaturesetting that the thermostatic device will open the switchmeansthe cam means being movable across the longitudinal axis of theother leg of the bimetal member ,to adjust the same.

Accordingly, it is an object of this invention to provide an improvedthermostatic device having one or moreof the novel features set forthabove or hereinafter shown or described.

Another object of this invention is to provide an improved controlsystem utilizing such a thermostatic device.

Other objects, uses and advantages of this invention are apparent from areading of this description which proceeds with reference totheaccompanying drawings forming a part thereof and wherein: I a

FIG. 1 is a front view of one embodiment of the thermo static device ofthis invention.

FIG. 2 is an enlarged view of the thermostatic device of FIG. 1 with thecover member thereof removed.

FIG. 3 is a reduced fragmentary view of the thermostatic device of FIG.2 with the selector means and another cover plate thereof removed toillustrate the electrical switch means and terminal means therefor.

FIG. 4 is an enlarged cross-sectional view taken on line 4-4 of FIG. 1.I

FIG. 5 is a cross-sectional view-taken on line 5-5 of FIG. 2.

FIG. 6 is a fragmentary rear view of the thermostatic device of FIG. 2.

FIG. 7 is an exploded perspective view of certain of the parts of thethermostatic device of FIG. 1.

FIG. 8 is a view similar to FIG. 3 and illustrates another thermostaticdevice of this invention.

FIG. 9 is a view similar to FIG. 4 and illustrates the thermostaticdevice of FIG. 8.

FIG. 10 is a fragmentary rear device of FIG. 8.

While the various features of this invention are hereinafter view of thethermostatic described and illustrated as being particularly adapted toprovide thermostatic control of a heating means for the rooms of abuilding or the like, it is to be understood that the thermostaticdevice of this invention can be utilized for controlling other devicesas desired. 1

Therefore, this invention is not to be limited to only the embodimentsillustrated in the drawings, because the drawings are merely utilized toillustrate one of the wide variety of uses of this invention.

Refen'ing now to FIGS. 1-7, the improved thermostatic device of thisinvention is generally indicated by the reference numeral 20 andcomprises a frame means 21 defined by a housing member 22 having arecess23 therein receiving an electrical switch means 24 in a mannerhereinafter described and being closed by a removable cover plate 26.The frame means 21 includes a bracket plate 27 secured to the housingmember 22 in any suitable manner so as to pivotally carry a selectormeans 28 pivotally mounted thereto by rivet means 29, the plate 27having depending L-shaped legs 30 riveted to the housing member 22 sothat the cover plate 27 is disposed in spaced relation relative to thepreviously described cover plate 26.

A cover plate 31 is adapted to be disposed against and be secured to thehousing member 22 in any suitable manner to cover the plate 27 asillustrated in FIG. 4, the cover means 31 having a slot 32 at one endthereof and through which an outwardly directed tang 33 of the selectormeans 28 can project so as to be manually grasped to move the selectormeans 28 relative to the frame means 21 while at the same timeindicating a temperature setting as provided by suitable scale means 34provided on the housing member 22 as illustrated in FIG. 1.

If desired, a suitable temperature indicating thermometer means 35can becarried by the cover means 31 and have an indicating pointer means 36viewable in a window means 37 cut in the cover member 31 as illustratedin FIG. 1.

The electrical switch means 24 comprises a snap blade 38 having opposedends 39 and 40 while being medially slotted to define three legs 41, 42and 43 with the outboard legs 42 and 43 being crimped at 44 to renderthe blade 38 snap acting in a manner fully disclosed and claimed inapplicants [15. Pat. No. 3,238,337. A leaf spring 45 is secured to theend 40 of the blade 38 as well as to the middle leg 41 by fasteningmeans 46 so as to bear against a set screw 47 threadedly disposed in athreaded bore 48 in an end wall 49 of the housing means 22, the end 40of the blade 38 being secured to a terminal plate 50 carried by thehousing means 22in the chamber 23 thereof and interconnected to anexternal terminal means 51 by an interconnecting cylindrical rivet means52 whereby the external terminal 51 is electrically interconnected tothe snap blade 38.

The other end 39 of the snap blade 38 carries contact means 53 adaptedto cooperate with a fixed contact means 54 carried by a terminal plate55 secured to the housing means 22 by a cylindrical rivet means 56 thatelectrically interconnects the plate 55 to external terminal means 57.The free end 39 of the snap blade 38 is adapted to snap between thefixed contact 54 and a set screw 58 threadedly carried in a threadedbore 59 in the end wall 49 of the housing means 22 except that the snapblade 38 has a natural tendency to always return its contact 53 againstthe fixed contact 54 as will be apparent hereinafter.

Another terminal plate 60 is disposed in the recess or cavity 23 of thehousing means 22 and is secured thereto by cylindrical rivet means 61that electrically interconnects the plate 60 to an external terminalmeans 62. An electrical resistance 63 has one of its leads 64electrically interconnected to the plate 60 while the other terminallead 65 thereof is electrically interconnected to the plate 50.

In this manner, a power source lead 66 from a power source 67 is adaptedto be electrically interconnected to the plate 60 at the terminal 62while the other power source lead 68 is adapted to be interconnected tothe plate 55 at the terminal 57. One end 69 of the means 70 thatcontrols a heating means, whether the means 70 is the heating meansitself or control means for a heat exchanger or the like, iselectrically interconnected to plate 50 at the terminal 51 by lead 71.The other end of the means 70 is interconnected by a lead 72 to theterminal 62 that leads to the terminal plate 60 as fully illustrated inFIG. 3.

Upon closure of contact 53 with contact 54 a current path from one sideof power source 67 through heating means 70 to the other side of powersource 67 is established. The current path includes lead 68 connected toone side of power source 67, terminal 57, plate 55, contact 54, contact53, snap blade 38, plate 50, terminal 51, lead 71, heating means 70,lead 72 connected to terminal 62 of plate 60 and continues via lead 66to the other side of power source 67. Since the electrical resistance 63is connected between plates 50 and 60 it is in parallel with the heatingmeans 70 and is therefore energized when heating means 70 is energized.

The cover member 26 that closes the open end of the chamber 23 includesan arcuate portion 73 that provides a recess means 74 for retaining theresistor 63 therein as fully illustrated in FIG. 4. In addition, thecover member 26 has bores 75 and 76 passing therethrough for a purposehereinafter described.

A U-shaped bimetal member 77 is provided and defines two parallel legs78 and 79 interconnected together at adjacent ends thereof to a U-shapedelbow portion 80 that is adapted to be disposed around a pivot pin 81carried within suitable apertures 82 of opposed cars 83 of the bracketmember 27 as illustrated in FIG. 4. The bracket member 27 has a pair ofdepending tan'gs 84 at one end 85 thereof that holds the elbow 80against the pi'votshaft 81 in the manner fully illustrated in FIG. 4.sothat the bimetal member 77 will pivot about the shaft 81'and, thus,about the frame means 21.

The leg 78 of the bimetal member has a tang 86 depending from the freeend 87 thereof to be engaged by an arcuate cam track 88 on the selectormeans 28 which is adapted to be A pivoted on the bracket means 27 sothat the cam track 88 will move across the longitudinal axis of the leg78 and bear against the end tang 86 thereof so as to adjust the pivotalposition of the bimetal member 77 relative to the frame means 21 and,thus, determine the temperature setting of the thermostatic device 20 aswill be apparent hereinafter.

' The other leg 79 of the bimetal member 77 has an internally threadedopening 89 passing through the free end 90 thereof and threadedlyreceiving an adjusting screw 91 which is alignable with the bore 75 inthe cover member 26 when the bimetal member 77 is assembled to thebracket means 27 as illustrated in FIG. 4.

An insulating rod or pin 92 is disposed in the bore 75 of the covermember 26 so that the opposed ends 93 and 94 of the pin 92 canrespectively engage the end 95 of the set screw 91 and the free end 39of the snap blade 38 of the electrical switch means 24.

The selector means 28 has an outwardly directed and arcuately bent'tang96 alignable with the other end 97 of the set screw 91 for a purposehereinafter described.

The operation of the thermostatic device 20 of this inventionas utilizedin the control system of this invention, which is generally indicated bythe reference numeral 98 in FIG. 3, will now be described.

The operator or the like positions the end 33 of the selector means 28relative to the scale 34 for a desired temperature setting so that thethermostatic device 20 will tend to maintain the temperature in the roomcontaining such thermostat 20 at the set temperature becausethethermostat 20 will operate the heating means 70 when the temperaturesensed in the room is below such setting of the end 33 of the selectormeans 28.

In particular, as long as the temperature in the room is above thetemperature setting of the end 33 of the selector means 28, the camtrack 88 has pivotally positioned the bimetal member 77 in such a mannerthat the leg 79 thereof has its free end 90 in such a position that leg79 of the bimetal member 77 through the plunger or pin 92 acts againstthe end 39 of the snap blade 38 to overcome the natural bias of the snapblade 38 and maintain the snap blade 38 against the set screw 58 wherebyno' current is adapted to flow between the spaced contacts 54 and 53and, thus, no current is permitted to flow through the heating means 70nor through resistance 63 connected in parallel across heating means 70.

However, when the temperature in the room falls below the selectedtemperature setting of the thermostat 20, the leg 79 of the bimetalmember 77 has warped to the left in FIG. 4 a distance sufiicient tocause the snap blade 38 to move its contact 53 against the fixed contact54 and, thus, complete the circuit through the heating means 70 to heatup the room carrying the thermostat 20. However, at this time, currentis also flowing through the resistor 63 which begins to heat up adjacentthe bimetal member 77 to cause the same to again open the contacts 53and 54 a short time before the room would reach such temperature shouldthe heating means 70 continue to operate so as to prevent adversetemperature overshooting condition. 7

Thus, it can be seen that the bimetal leg 79 by warping back and forthin response to temperature change will tend to maintain the temperatureof the room at the temperature set by the selector means 28.

Ifdesired, movement of the end 33 of the selector means 28 completely tothe left in FIG. 1 can cause the tang 96 thereof to bear against the end97 of the set screw 91 in such a manner that the same will positivelyforce the plunger means 92 and free end 39 of the snap blade 38 awayfrom the fixed contact 54 and, thus, against the set screw 58 so as tomaintain a positive ofi condition of the thermostat 20. However, if sucha positive off of the thermostat 20 is not desired for the snap blademeans 38 thereof, the tang 96 can be bent to be coplanar with theremainder of the selector means 28 so that the same will not act on theend 97 of the set screw 91 so that no positive 013' condition will beprovided by the selector means 28.

Should it be desired to provide a positive foff position of the controlsystem 98 when the selector means 28 is moved to an ofF positionthereof, a second electrical switch means can be provided for thethermostat 20. The second electrical switch is connected to open oneside of the power source with switch means 24 connected to open andclose the other side of the power source. Upon moving selector means 28to the off position at least one side of the power source will be brokenregardless of the position of the switch means 24.

In particular, reference is now made to FIGS. 8, 9 and 10 whereinanother thermostatic device of this invention is generally indicated bythe reference numeral 20A and parts thereof identical to the thermostat20 previously described are indicated by like reference numeralsfollowed by the reference letter A.

As illustrated in FIGQ9, the thermostat device 20A is substantiallyidentical to the thermostat device 20 previously described except thatanother switch means 99 is disposed in the chamber 23A and comprises'aswitch blade 100 having one end 10] thereof secured to the housing means22A bya cylindrical rivet 102, FIG. 8, that is electricallyinterconnected to an external tenninal means 62A. The switch blade 100is electrically interconnected to the switch blade 38 by the resistormeans 63A having one of its leads 64A interconnected to the switch blade100 while the other lead 65A thereof is interconnected to the plate 50Athat is electrically interconnected to the snap blade 38A. The other end103 of the switch blade 100 can'ies a contact means 104 which isnormally disposed in electrical contact with a fixed contact 105 carriedby a contact blade 106 secured to the housing means 22A and beinginterconnected by a cylindrical rivet 107 to an external terminal means108 that is adapted to-be interconnected to one side of the power source67A of FIG. 8 by a lead 66A. The other side of power source 67A isinterconnected to the fixed contact 54A of the snap switch 24A in themanner previously described. The heating means 70A is connected vialeads 71A and 72A to terminals 51A and 62A respectively.

Thus,in order for the heating means 70A to be operated by the powersource 67A, the switch means 99 must be in a closed position as well asthe switch means 24A.

Another insulating rod or pin 109 is disposed in the bore I 76A of thecover member 26A and has one opposed end 110 adapted to bear againstswitch blade 100 and the other op posed end 111 adapted to be alignablewith another arcuate tang means 1 12 of the selector means 28A.

In this manner, only when the selector means 28A of the thermostat Ashown in FIG. 9 is moved completely to the left as viewed in FIG. 8 willthe tank 112 of the selector means 28A act against the end 111 of theplunger means 109 sufficiently to cause the plunger means 109 to movethe switch blade 100 tothe right in FIG. 9 a distance sufiicient to openthe contacts 104 and 105 so that no electrical current can flow throughthe heating means 70A until the selector means 28A shownin FIG. 9 isagain moved to the right as viewed in FIG. 8 to pennit the switch means99 to close. If desired, the other tang 96A of the selector means 28Acan also cause positive opening of the switch means 24A in the mannerpreviously described for the thermostat 20 at the same time the switchmeans 99 is being positively maintained in an open position thereof toprovide a double pole thermostat.

Therefore, it can be seen that an improved thermostatic ,deviceisprovided by this invention as well as an improved control systemutilizing such a thermostatic device. While the form of theinvention nowpreferred has been disclosed as required by the patent statutes, otherforms may be utilized, all coming within the scope of the claims whichfollow.

What is claimed is:

1. A thermostatic device having a frame means, electrical switch meanscarried by said frame means, a U-shaped bimetal member defining a pairof legs interconnected together at adjacent ends thereof by an elbowportion, said elbow portion pivotally mounting said bimetal member tosaid frame means, plunger means movably carried by said frame means andbeing disposed between one of said legs of said bimetal member and saidswitch means to operate said switch means in relation to-the position ofsaid one leg relative to said frame means, and cam means movably carriedby said .frame means and acting on the other leg of said bimetal memberto adjust the pivotal position of said bimetal member and, thus, thetemperature setting that said thermostatic devicewill open said switchmeans, said cam means being movable across the longitudinal axis of saidother leg of said bimetal member to adjust the same.

2. A thermostatic device as set forth in claim 1 wherein said cam meanscomprises part of a manual selector means for said device.

, 3. A thermostatic device as set forth in claim 2 wherein said .manualselector means has means for operatively engaging against said one legof said bimetal member to directly move said one leg and said plungermeans to a position that opens said switch means.

4. A thermostatic device as set forth in claim 3 wherein said means foroperatively engaging against said one leg of said bimetal membercomprises another cam means.

5. A thermostatic device having a frame means, electrical switch meanscarried by said frame means, a U-shaped bimetal member defining a pairof legs interconnected together at adjacent ends thereof by an elbowportion, said elbow portion pivotally mounting said bimetal member tosaid frame means,

plunger means movably carried by said frame means and pivotally mountingsaid bimetal member to said frame means,

plunger means movably carried by said frame means and being disposedbetween one of said legs of said bimetal member and said switch means tooperate said switch means in relation tothe position of said one legrelative to said frame means, and cam means movably carried by saidframe means and acting on the other leg of said bimetal member to adjustthe pivotal position of said bimetal member and, thus, the temperaturesetting that said thermostatic device will open said switch means, saidcam means being movable across the longitudinal axis of said other legof said bimetal member to ad just the same, said cam means comprisingpart of a manual selector means for said device, said selector meanshaving a tang that is to be manually grasped to move said selectormeans, said tang providing temperature setting and indicating means forsaid device.

8. A thermostatic device having a frame means, electrical switch meanscarried by said frame means, a U-shaped bimetal member defining a pairof legs interconnected together at adjacent ends thereof by an elbowportion, said elbow portion pivotally mounting said bimetal member tosaid frame means, plunger means movably carried by said frame means andbeing disposed between one of said legs of said bimetal member and saidswitch means to operate said switch means in relation to the position ofsaid one leg relative to said frame means, and'cam means movably carriedby said frame means and acting on the other leg of said bimetal memberto adjust the pivotal position of said bimetal member, and, thus, thetemperature setting that said thermostatic device will open said switchmeans, said cam means being movable across the longitudinal axis of saidother leg of said bimetal member to adjust the same, said one leg ofsaid bimetal member carrying an adjusting member having one end engagingsaid plunger means. g

9. A thermostatic device as set forth in claim 8 wherein said adjustingmember is disposed at the free end of said one leg of said bimetalmember.

10. A thermostatic device as set forth in claim 9 wherein said manualselector means has means for engaging against the being disposed betweenone of said legs of said bimetal j member and said switch means tooperate said switch means selector means for said device, said manualselector means.

having means for operatively engaging against said one leg of saidbimetal member to directly move said one leg and said plunger means to aposition that opens said switch means, said means for operativelyengaging against said one leg of said bimetal member comprises anothercam means, said other cam means comprising an arcuately disposed camtang of said selector means.

other end of said adjusting member to directly move said one leg andsaid plunger means to a position that opens said switch means.

11. A thermostatic device having a frame means, electrical switch meanscarried by said frame means, a U-shaped bimetal member defining a pairof legs interconnected together at adjacent ends thereof by an elbowportion, said elbow portion.

pivotally mounting said bimetal member to said frame means, plungermeans movably carried by said frame means and i being disposed betweenone of said legs of said bimetal member and said switch means to operatesaid switch means in relation to the position of said one leg relativeto said frame means, cam means movably carried by said frame means andacting on the other leg of said bimetal member to adjust the pivotalposition of said bimetal member and, thus, the temperature setting thatsaid thermostatic device will open said switch means, said cam meansbeing movable across the longitudinal axis of said other leg of saidbimetal member to adjust the same, and another electrical switch meanscarried by said frame means, said other switch means with said firstmentioned switch means permitting said thermostatic device to beconnected for double pole operation.

12. A thermostatic device as set forth in claim 11 wherein said cammeans comprises part of a manual selector means for said device, saidframe means carrying another movable plunger means for operating saidother switch means, said selector means having means for engaging andmoving said other plunger means to open said other switch means.

13. A thermostatic device as set forth in claim 12 wherein said meansfor engaging said-other plunger means comprises another cam meanscarried by said selector means.

14. A thermostatic device as set forth in claim 13 wherein said othercam means comprises an arcuately disposed cam tang of said selectormeans.

15. A thermostatic device having a frame means, electrical switch meanscarried by said frame means, a U-shaped bimetal member defining a pairof legs interconnected together at adjacent ends thereof by an elbowportion, said elbow portion pivotally mounting said bimetal member tosaid frame means, plunger means movably carried by said frame means andbeing disposed between one of said legs of said bimetal member and saidswitch means to operate said switch means in relation to the position ofsaid one leg relative to said frame means, and cam means movably carriedby said frame means and acting on the other leg of said bimetal membertoadjust the pivotal position of said bimetal member and, thus, thetemperature setting that said thermostatic device will open said switchmeans, said cam means being movable across the iongitudinal axis of saidother leg of said bimetal member to adjust the same, said frame meanscarrying a pivot pin and havingtang means disposed adjacent said pivotpin means, said elbow of said bimetal member receiving said pivot pinand being disposed between said tang means and said pivot pin to bepivotally mounted to said frame means.

16. In a control system having a source of electrical current and anelectrically operated heating means, the improvement comprising athermostatic device having a frame means, electrical switchmeans carriedby said frame means and being electrically interconnected to said sourceand to said heating means to interconnect said source to said heatingmeans when said switch means is closed and to disconnect said sourcefrom said heating means when said'switch means is open, a U- shapedbimetal member defining a pair of legs-interconnected together atadjacent ends thereof by an elbow portion, said elbow portion pivotallymounting said bimetal member to said frame means, plunger means movablycarried by said frame means and beingdisposed between one of said legsof said bimetal member and said switch means to operate said switchmeans in relation to the position of said one leg relative to said framemeans, and cam means movably carried by said frame means and acting onthe other leg of said bimetal member to adjust the pivotal position ofsaid bimetal member and, thus, the temperature setting that saidthermostatic device will open said switch means, said cam means beingmovable across the longitudinal axis of said other leg of said bimetalmember to adjust the same.

17. In a control system as set forth in claim 16, the furtherimprovement wherein said cam means comprises part of a manual selectormeans for said device.

18. In a control system as set forth in claim 17, the furtherimprovement wherein said manual selector means has means for operativelyengaging against said one leg of said bimetal member to directly movesaid one leg-and said plunger means to a position that opens said switchmeans.

19. ln a control system having a source of electrical current and anelectrically operated heating means, the improvement comprising athermostatic device having a frame means, electrical switch meanscarried by said frame means and being electrically interconnected tosaid source and to said heating means to interconnect said source. tosaid heating means when said switch means is closed and to disconnectsaid source from said heating means when said switch means is open, a U-shaped bimetal member defining a pair of legs interconnected together atadjacent ends thereof by an elbow portion, said elbow portion pivotallymounting said bimetal member to said frame means, plunger means movablycarried by said frame means and being disposed between one of said legsof said bimetal member and saidswitch means to operate said switch meansin relation to the position of said one leg relative to said framemeans, and cam means movably carried by said frame means and acting onthe other leg of said bimetal member to adjust the pivotal position ofsaid bimetal member and, thus, the temperature setting that saidthermostatic device will open said switch means, said cam means beingmovable across the longitudinal axis of said other leg of said bimetalmember to adjust the same, said cam means comprising part of a manualselector means for said device, said manual selector means having meansfor operatively engaging against said one leg of said bimetal member todirectly move said one leg and said plunger means to a position thatopens said switch means, said means for operatively engaging againstsaid one leg of said bimetal member comprising another cam means.

20. In a control system as setforth in claim 19, the further improvementwherein said other cam means comprises an arcuately disposed cam tang ofsaid selector means.

21. In a control system as set forth in claim 17, the furtherimprovement wherein said cam means comprises a cam track on saidselector means.

22. In a control system having a source of electrical current and anelectrically operated heating means, the improvement comprising athermostatic device having a frame means, electrical switch meanscarried by said frame means and being electrically interconnected tosaid source and to said heating means to interconnect said source tosaid heating means when said switch means is closed and to disconnectsaid source from said heating means when said switch means is open, a U-shaped bimetal member defining a pair of legs interconnected together atadjacent ends thereof by an elbow portion, said elbow portion pivotallymounting said bimetal member to said frame means.. plunger means movablycarried by said frame means and being disposed between one of said legsof said bimetal member and said switch means to operate said switchmeans in relation to the position of said one leg'relative to said framemeans, and cam means movably carried by said frame means and acting onthe other leg of said bimetal member to adjust the pivotal position ofsaid bimetal'm'ember. and, thus, the temperature setting that saidthermostatic device will open said switch means, said cam means beingmovable across the longitudinal axis of said other legvof said bimetalmember to adjust the same, said cam means comprising part of a manualselector means for said device, said selector means having a tang thatis to be manually grasped to move said selector means, said tangproviding temperature setting and indicating means for said device. I

23. In a control system having a source of electrical current and anelectrically operated heating means, the improvement comprising athermostatic device having a frame means, elec trical switch meanscarried by said frame means and being electrically interconnected tosaid source and to said heating means to interconnect said source tosaid heating means when said switch means is closed and to disconnectsaid source from said heating means when said switch means is open, a Ushaped bimetal member defining a pair of legs interconnected together atadjacent ends thereof by an elbow portion, said elbow portion pivotallymounting said bimetal member to said frame means, plunger means movablycarried by said frame -means and being disposed between one of said legsof said bimetal member and said switch means to operate said switchmeans in relation to the position of said one leg relative to said framemeans, and cam means movablycarried by said frame means and acting onthe other leg of said bimetal member to adjust the pivotal position ofsaid bimetal member and, thus, the temperature setting that saidthermostatic device will open said switch means, said cam means beingmovable across the longitudinal axis of said other leg of said bimetalmember to adjust the same, said one leg of said bimetal member carryingan adjusting member having one end engaging said plunger means,

24. In a control system as set forth in claim 23, the furtherimprovement wherein said adjusting member is disposed at directly movesaid one leg and said plunger means to a position that opens said switchmeans.

26. In a control system having a source of electrical current and anelectrically operated heating means, the improvement comprising athermostatic device having a frame means, electrical switch meanscarried by said frame means and being electrically interconnected tosaid source and to said heating means to interconnect said source tosaid heating means when said switch means is closed and to disconnectsaid source from said heating means when said switch means is open, a U-shaped bimetal member defining a pair of legs interconnected together atadjacent ends thereof by an elbow portion, said elbow portion pivotallymounting said bimetal member to said frame means, plunger means movablycarried by said frame means and being disposed between one of said legsof said bimetal member and said switch means to operate said switchmeans in relation to the position of said one leg relative to said framemeans, and cam means movably carried by said frame means and acting onthe other leg of said bimetal member to adjust the pivotal position ofsaid bimetal member and, thus, the temperature setting that saidthermostatic device will open said switch means, said cam means beingmovable across the longitudinal axis of said other leg of said bimetalmember to adjust the same, and another electrical switch means carriedby said frame means, said other switch means being electricallyinterconnected in series between one side of said source and one end ofsaid electrically operated heating means and said first-named switchmeans being electrically interconnected in series between the other sideof said source and the other end of said electrically operated heatingmeans.

27. In a control system as set forth in claim 26, the furtherimprovement wherein said cam means comprises part of a manual selectormeans for said device, said frame means carrying another movable plungermeans for operating said other switch means, said selector means havingmeans for engaging and moving said other plunger means to open saidother switch means.

28. in a control system as set forth in claim 27, the furtherimprovement wherein said means for engaging said other plunger meanscomprises another cam means carried by said selector means, j

29. In a control system as set forth in claim 28, the furtherimprovement wherein said other cam means comprises an arcuately disposedcam tang of said selector means.

30. In a control system having a source of electrical current and anelectrically operated heating means, the improvement comprising athermostatic device having a frame means, electrical switch meanscarried by said frame means and being electrically interconnected tosaid source and to said heating means to interconnect said source tosaid heating means when said switch means is closed and to disconnectsaid source from said heating means when said switch means is open, a U-shaped bimetal member defining a pair of legs interconnected together atadjacent ends thereof by an elbow portion, said elbow portion pivotallymounting said bimetal member to said frame means, plunger means movablycarried by said frame means and being disposed between one of said legsof said bimetal member and said switch means to operate said switchmeans in relation to the position of said one leg relative to said framemeans, and cam means movably carried by said frame means and acting onthe other leg of said bimetal member to adjust the pivotal position ofsaid bimetal member to adjust the pivotal position of said bimetalmember and, thus, the temperature setting that said thermostatic devicewill open said switch means, said cam means being movable across thelongitudinal axis of said other leg of said bimetal member to adjust thesame, said frame means carrying a pivot pin and having tang meansdisposed adjacent said pivot pin means, said elbow of said bimetalmember receiving said pivot pin and being disposed between said tangmeans and said pivot pin to be pivotally mounted to said frame means.

1. A thermostatic device having a frame means, electrical switch meanscarried by said frame means, a U-shaped bimetal member defining a pairof legs interconnected together at adjacent ends thereof by an elbowportion, said elbow portion pivotally mounting said bimetal member tosaid frame means, plunger means movably carried by said frame means andbeing disposed between one of said legs of said bimetal member and saidswitch means to operate said switch means in relation to the position ofsaid one leg relative to said frame means, and cam means movably carriedby sAid frame means and acting on the other leg of said bimetal memberto adjust the pivotal position of said bimetal member and, thus, thetemperature setting that said thermostatic device will open said switchmeans, said cam means being movable across the longitudinal axis of saidother leg of said bimetal member to adjust the same.
 2. A thermostaticdevice as set forth in claim 1 wherein said cam means comprises part ofa manual selector means for said device.
 3. A thermostatic device as setforth in claim 2 wherein said manual selector means has means foroperatively engaging against said one leg of said bimetal member todirectly move said one leg and said plunger means to a position thatopens said switch means.
 4. A thermostatic device as set forth in claim3 wherein said means for operatively engaging against said one leg ofsaid bimetal member comprises another cam means.
 5. A thermostaticdevice having a frame means, electrical switch means carried by saidframe means, a U-shaped bimetal member defining a pair of legsinterconnected together at adjacent ends thereof by an elbow portion,said elbow portion pivotally mounting said bimetal member to said framemeans, plunger means movably carried by said frame means and beingdisposed between one of said legs of said bimetal member and said switchmeans to operate said switch means in relation to the position of saidone leg relative to said frame means, and cam means movably carried bysaid frame means and acting on the other leg of said bimetal member toadjust the pivotal position of said bimetal member and, thus, thetemperature setting that said thermostatic device will open said switchmeans, said cam means being movable across the longitudinal axis of saidother leg of said bimetal member to adjust the same, said cam meanscomprising part of a manual selector means for said device, said manualselector means having means for operatively engaging against said oneleg of said bimetal member to directly move said one leg and saidplunger means to a position that opens said switch means, said means foroperatively engaging against said one leg of said bimetal membercomprises another cam means, said other cam means comprising anarcuately disposed cam tang of said selector means.
 6. A thermostaticdevice as set forth in claim 2 wherein said cam means comprises a camtrack on said selector means.
 7. A thermostatic device having a framemeans, electrical switch means carried by said frame means, a U-shapedbimetal member defining a pair of legs interconnected together atadjacent ends thereof by an elbow portion, said elbow portion pivotallymounting said bimetal member to said frame means, plunger means movablycarried by said frame means and being disposed between one of said legsof said bimetal member and said switch means to operate said switchmeans in relation to the position of said one leg relative to said framemeans, and cam means movably carried by said frame means and acting onthe other leg of said bimetal member to adjust the pivotal position ofsaid bimetal member and, thus, the temperature setting that saidthermostatic device will open said switch means, said cam means beingmovable across the longitudinal axis of said other leg of said bimetalmember to adjust the same, said cam means comprising part of a manualselector means for said device, said selector means having a tang thatis to be manually grasped to move said selector means, said tangproviding temperature setting and indicating means for said device.
 8. Athermostatic device having a frame means, electrical switch meanscarried by said frame means, a U-shaped bimetal member defining a pairof legs interconnected together at adjacent ends thereof by an elbowportion, said elbow portion pivotally mounting said bimetal member tosaid frame means, plunger means movably carried by said frame means andbeing disposed between one of said legs of said bimetal member and saidswitch means to operate said switch means in rElation to the position ofsaid one leg relative to said frame means, and cam means movably carriedby said frame means and acting on the other leg of said bimetal memberto adjust the pivotal position of said bimetal member, and, thus, thetemperature setting that said thermostatic device will open said switchmeans, said cam means being movable across the longitudinal axis of saidother leg of said bimetal member to adjust the same, said one leg ofsaid bimetal member carrying an adjusting member having one end engagingsaid plunger means.
 9. A thermostatic device as set forth in claim 8wherein said adjusting member is disposed at the free end of said oneleg of said bimetal member.
 10. A thermostatic device as set forth inclaim 9 wherein said manual selector means has means for engagingagainst the other end of said adjusting member to directly move said oneleg and said plunger means to a position that opens said switch means.11. A thermostatic device having a frame means, electrical switch meanscarried by said frame means, a U-shaped bimetal member defining a pairof legs interconnected together at adjacent ends thereof by an elbowportion, said elbow portion pivotally mounting said bimetal member tosaid frame means, plunger means movably carried by said frame means andbeing disposed between one of said legs of said bimetal member and saidswitch means to operate said switch means in relation to the position ofsaid one leg relative to said frame means, cam means movably carried bysaid frame means and acting on the other leg of said bimetal member toadjust the pivotal position of said bimetal member and, thus, thetemperature setting that said thermostatic device will open said switchmeans, said cam means being movable across the longitudinal axis of saidother leg of said bimetal member to adjust the same, and anotherelectrical switch means carried by said frame means, said other switchmeans with said first mentioned switch means permitting saidthermostatic device to be connected for double pole operation.
 12. Athermostatic device as set forth in claim 11 wherein said cam meanscomprises part of a manual selector means for said device, said framemeans carrying another movable plunger means for operating said otherswitch means, said selector means having means for engaging and movingsaid other plunger means to open said other switch means.
 13. Athermostatic device as set forth in claim 12 wherein said means forengaging said other plunger means comprises another cam means carried bysaid selector means.
 14. A thermostatic device as set forth in claim 13wherein said other cam means comprises an arcuately disposed cam tang ofsaid selector means.
 15. A thermostatic device having a frame means,electrical switch means carried by said frame means, a U-shaped bimetalmember defining a pair of legs interconnected together at adjacent endsthereof by an elbow portion, said elbow portion pivotally mounting saidbimetal member to said frame means, plunger means movably carried bysaid frame means and being disposed between one of said legs of saidbimetal member and said switch means to operate said switch means inrelation to the position of said one leg relative to said frame means,and cam means movably carried by said frame means and acting on theother leg of said bimetal member to adjust the pivotal position of saidbimetal member and, thus, the temperature setting that said thermostaticdevice will open said switch means, said cam means being movable acrossthe longitudinal axis of said other leg of said bimetal member to adjustthe same, said frame means carrying a pivot pin and having tang meansdisposed adjacent said pivot pin means, said elbow of said bimetalmember receiving said pivot pin and being disposed between said tangmeans and said pivot pin to be pivotally mounted to said frame means.16. In a control system having a source of electrical current and anelectrically operated heating means, the improvement Comprising athermostatic device having a frame means, electrical switch meanscarried by said frame means and being electrically interconnected tosaid source and to said heating means to interconnect said source tosaid heating means when said switch means is closed and to disconnectsaid source from said heating means when said switch means is open, aU-shaped bimetal member defining a pair of legs interconnected togetherat adjacent ends thereof by an elbow portion, said elbow portionpivotally mounting said bimetal member to said frame means, plungermeans movably carried by said frame means and being disposed between oneof said legs of said bimetal member and said switch means to operatesaid switch means in relation to the position of said one leg relativeto said frame means, and cam means movably carried by said frame meansand acting on the other leg of said bimetal member to adjust the pivotalposition of said bimetal member and, thus, the temperature setting thatsaid thermostatic device will open said switch means, said cam meansbeing movable across the longitudinal axis of said other leg of saidbimetal member to adjust the same.
 17. In a control system as set forthin claim 16, the further improvement wherein said cam means comprisespart of a manual selector means for said device.
 18. In a control systemas set forth in claim 17, the further improvement wherein said manualselector means has means for operatively engaging against said one legof said bimetal member to directly move said one leg and said plungermeans to a position that opens said switch means.
 19. In a controlsystem having a source of electrical current and an electricallyoperated heating means, the improvement comprising a thermostatic devicehaving a frame means, electrical switch means carried by said framemeans and being electrically interconnected to said source and to saidheating means to interconnect said source to said heating means whensaid switch means is closed and to disconnect said source from saidheating means when said switch means is open, a U-shaped bimetal memberdefining a pair of legs interconnected together at adjacent ends thereofby an elbow portion, said elbow portion pivotally mounting said bimetalmember to said frame means, plunger means movably carried by said framemeans and being disposed between one of said legs of said bimetal memberand said switch means to operate said switch means in relation to theposition of said one leg relative to said frame means, and cam meansmovably carried by said frame means and acting on the other leg of saidbimetal member to adjust the pivotal position of said bimetal memberand, thus, the temperature setting that said thermostatic device willopen said switch means, said cam means being movable across thelongitudinal axis of said other leg of said bimetal member to adjust thesame, said cam means comprising part of a manual selector means for saiddevice, said manual selector means having means for operatively engagingagainst said one leg of said bimetal member to directly move said oneleg and said plunger means to a position that opens said switch means,said means for operatively engaging against said one leg of said bimetalmember comprising another cam means.
 20. In a control system as setforth in claim 19, the further improvement wherein said other cam meanscomprises an arcuately disposed cam tang of said selector means.
 21. Ina control system as set forth in claim 17, the further improvementwherein said cam means comprises a cam track on said selector means. 22.In a control system having a source of electrical current and anelectrically operated heating means, the improvement comprising athermostatic device having a frame means, electrical switch meanscarried by said frame means and being electrically interconnected tosaid source and to said heating means to interconnect said source tosaid heating means when said switch means is closed and to disconnectsaid source from said heAting means when said switch means is open, aU-shaped bimetal member defining a pair of legs interconnected togetherat adjacent ends thereof by an elbow portion, said elbow portionpivotally mounting said bimetal member to said frame means, plungermeans movably carried by said frame means and being disposed between oneof said legs of said bimetal member and said switch means to operatesaid switch means in relation to the position of said one leg relativeto said frame means, and cam means movably carried by said frame meansand acting on the other leg of said bimetal member to adjust the pivotalposition of said bimetal member and, thus, the temperature setting thatsaid thermostatic device will open said switch means, said cam meansbeing movable across the longitudinal axis of said other leg of saidbimetal member to adjust the same, said cam means comprising part of amanual selector means for said device, said selector means having a tangthat is to be manually grasped to move said selector means, said tangproviding temperature setting and indicating means for said device. 23.In a control system having a source of electrical current and anelectrically operated heating means, the improvement comprising athermostatic device having a frame means, electrical switch meanscarried by said frame means and being electrically interconnected tosaid source and to said heating means to interconnect said source tosaid heating means when said switch means is closed and to disconnectsaid source from said heating means when said switch means is open, aU-shaped bimetal member defining a pair of legs interconnected togetherat adjacent ends thereof by an elbow portion, said elbow portionpivotally mounting said bimetal member to said frame means, plungermeans movably carried by said frame means and being disposed between oneof said legs of said bimetal member and said switch means to operatesaid switch means in relation to the position of said one leg relativeto said frame means, and cam means movably carried by said frame meansand acting on the other leg of said bimetal member to adjust the pivotalposition of said bimetal member and, thus, the temperature setting thatsaid thermostatic device will open said switch means, said cam meansbeing movable across the longitudinal axis of said other leg of saidbimetal member to adjust the same, said one leg of said bimetal membercarrying an adjusting member having one end engaging said plunger means.24. In a control system as set forth in claim 23, the furtherimprovement wherein said adjusting member is disposed at the free end ofsaid one leg of said bimetal member.
 25. In a control system as setforth in claim 24, the further improvement wherein said manual selectormeans has means for engaging against the other end of said adjustingmember to directly move said one leg and said plunger means to aposition that opens said switch means.
 26. In a control system having asource of electrical current and an electrically operated heating means,the improvement comprising a thermostatic device having a frame means,electrical switch means carried by said frame means and beingelectrically interconnected to said source and to said heating means tointerconnect said source to said heating means when said switch means isclosed and to disconnect said source from said heating means when saidswitch means is open, a U-shaped bimetal member defining a pair of legsinterconnected together at adjacent ends thereof by an elbow portion,said elbow portion pivotally mounting said bimetal member to said framemeans, plunger means movably carried by said frame means and beingdisposed between one of said legs of said bimetal member and said switchmeans to operate said switch means in relation to the position of saidone leg relative to said frame means, and cam means movably carried bysaid frame means and acting on the other leg of said bimetal member toadjust the pivotal position of said bimetal member and, thus, theTemperature setting that said thermostatic device will open said switchmeans, said cam means being movable across the longitudinal axis of saidother leg of said bimetal member to adjust the same, and anotherelectrical switch means carried by said frame means, said other switchmeans being electrically interconnected in series between one side ofsaid source and one end of said electrically operated heating means andsaid first-named switch means being electrically interconnected inseries between the other side of said source and the other end of saidelectrically operated heating means.
 27. In a control system as setforth in claim 26, the further improvement wherein said cam meanscomprises part of a manual selector means for said device, said framemeans carrying another movable plunger means for operating said otherswitch means, said selector means having means for engaging and movingsaid other plunger means to open said other switch means.
 28. In acontrol system as set forth in claim 27, the further improvement whereinsaid means for engaging said other plunger means comprises another cammeans carried by said selector means.
 29. In a control system as setforth in claim 28, the further improvement wherein said other cam meanscomprises an arcuately disposed cam tang of said selector means.
 30. Ina control system having a source of electrical current and anelectrically operated heating means, the improvement comprising athermostatic device having a frame means, electrical switch meanscarried by said frame means and being electrically interconnected tosaid source and to said heating means to interconnect said source tosaid heating means when said switch means is closed and to disconnectsaid source from said heating means when said switch means is open, aU-shaped bimetal member defining a pair of legs interconnected togetherat adjacent ends thereof by an elbow portion, said elbow portionpivotally mounting said bimetal member to said frame means, plungermeans movably carried by said frame means and being disposed between oneof said legs of said bimetal member and said switch means to operatesaid switch means in relation to the position of said one leg relativeto said frame means, and cam means movably carried by said frame meansand acting on the other leg of said bimetal member to adjust the pivotalposition of said bimetal member to adjust the pivotal position of saidbimetal member and, thus, the temperature setting that said thermostaticdevice will open said switch means, said cam means being movable acrossthe longitudinal axis of said other leg of said bimetal member to adjustthe same, said frame means carrying a pivot pin and having tang meansdisposed adjacent said pivot pin means, said elbow of said bimetalmember receiving said pivot pin and being disposed between said tangmeans and said pivot pin to be pivotally mounted to said frame means.